Determination of patient circuit disconnect in leak-compensated ventilatory support

A method of detecting disconnection of a ventilation system during delivery of therapy to a patient comprising:

• generating an actual leak equation based on a leak model and measurements taken during the delivery of therapy to the patient;
• generating a maximum leak equation based on the leak model, and a maximum allowed leakage at a specified pressure;
• measuring pressure in the ventilation system during a current therapy period;
• and
• calculating an actual leak from the ventilation system for the current therapy period based on the pressure using the actual leak equation;
• calculating a maximum allowable leak from the ventilation system for the current therapy period based on the pressure using the maximum leak equation;
• and
• selecting, based on a comparison of the actual leak and the maximum allowable leak, one of at least two ventilator connection states.

A pressure support system comprising:

• a pressure generating system adapted to generate a flow of breathing gas;
• a ventilation system including a patient interface device;
• one or more sensors operatively coupled to the pressure generating system or the ventilation system, each sensor capable of generating an output indicative of a pressure of the breathing gas;
• a processor;
• an actual leak estimation module that calculates actual leakage in the ventilation system based on pressure and a predetermined actual leak equation;
• a maximum allowable leak estimation module that calculates maximum allowable leakage in the ventilation system based on pressure and a predetermined maximum allowable leak equation;
• and
• a disconnect monitoring module that generates one or more alarms based on a comparison of the actual leakage and the maximum allowable leakage.

A computer-readable medium comprising computer-executable instruction for performing a method of detecting disconnection of a ventilation system during delivery of therapy to a patient, the method comprising:

• generating an actual leak equation based on a leak model and measurements taken during the delivery of therapy to the patient;
• generating a maximum leak equation based on the leak model, and a maximum allowed leakage at a specified pressure;
• measuring pressure in the ventilation system during a current therapy period;
• and
• calculating an actual leak from the ventilation system for the current therapy period based on the pressure using the actual leak equation;
• calculating a maximum allowable leak from the ventilation system for the current therapy period based on the pressure using the maximum leak equation;
• and
• selecting, based on a comparison of the actual leak and the maximum allowable leak, one of at least two ventilator connection states.